In commercial garbage disposers used, for example, in business establishments such as restaurants, the usage of water is high because water flow levels must be set for the maximum grind rate in order to prevent drain blockage Attendants will turn on the disposer and water at a high flow rate and allow both to run continuously even though the unit is grinding at a low rate or running idle
Various controls for garbage grinders have heretofore been proposed. For example, U.S. Pat. No. 2,785,863 discloses the use of a time delay relay to operate a solenoid valve, which delays shutoff of water for a brief time after the motor is turned off. In accordance with another suggestion, water can be kept flowing as long as the motor is spinning in order to prevent dry grinding while the motor is coasting during shutoff. See, for example, U.S. Pat. No. 2,880,941. It has also been proposed to monitor conductivity between the rotating and stationary elements as suggested in U.S. Pat. No. 3,344,996. However, the rotating and stationary shredders must, then, be electrically insulated. A still further suggestion has been to monitor noise level vibration, or flow, through an outlet so that the disposer is automatically shut off when it is finished grinding See U.S. Pat. No. 3,545,684. A need has continued to exist, however, for an approved system for ensuring that adequate water is provided to a disposer, but also that water is not wasted.